An Anomaly of Nature: Tiger Sharks in Honokohau, Hawaii Marine Biology

Another summer day in Hawaii begins with the sun cresting over the ridge of Mauna Loa.
Inside Honokohau harbor, the busiest harbor on the Big Island of Hawaii, numerous commercial and recreational vessels begin their preparations for their day’s activities on the ocean. The sea is calm and the air still as we load our gear onto our vessel. From my many years of personal experience diving this bay, I knew it would be another pristine day just outside the Harbor.

THE HARBOR

Nested inside Kaloko-Honokōhau National Historical Park, along the southern boundary, an anomaly of nature exists. The bay has been called many names: “Crescent Beach”, “Alua Bay”, “Dog Beach” (because dogs are allowed to run here), “Naked Beach” (since it was once a nude beach), “The Can Dive” (for the infamous green aid to navigation), “Manta Ray Bay” (because manta rays frequent the cleaning stations), “The Harbor”, and now, as I call it in summer, “Tiger Alley.”
The harbor proper, where the vessels are sheltered, was built by the US Army Corps of Engineers in 1970. The lava rock was blasted with dynamite and carved with large hydraulic chisels to form a protective harbor that houses more than 230 vessel slips. Of the approximate 190 km of shoreline along the west side of the Big Island, this is the busiest bay.
Starting many hours before dawn and through the hours after midnight, vessels enter and leave the harbor. At the “wash down” area, many different vessels gather to either begin their preparations for the work day ahead or are finishing the clean up from hours, days, or even weeks at sea.

THE NATURE

As vessels leave the harbor mouth, a single green buoy, an aid to navigation, assists their path. Underwater, the amount of biodiversity along this path is greater than in most hikes through dense rain-forests. If you could remove the water from the bay, you would see an expansive underwater coral reef playground. The wealth of nature along this path boggles many marine naturalists and scientists.
On any given day, the usual players can easily be found. As you jump off the lava rock, you are immediately part of a young and healthy coral reef ecosystem. Humuhumu-nukunuku-āpua’a (Reef Triggerfish; Rhinecanthus rectangles), the official State Fish of Hawaii, are aggressive to anyone who swims within vicinity of their nests. Schools of Yellowfin Goatfish (Mulloidichthys vanicolensis; Hn*: week ‘ula), Raccoon Butterflyfish (Chaetodon lunula; Hn: kīkākapu), and Heller’s Barracuda (Sphyraena helleri; Hn: Kawele’ā) are found at their usual spots on the reef. Spotted Eagle Rays (Aetobatus narinari; Hn: Hīnīmanu) fly about like birds of prey, visiting the numerous cleaning stations that are frequented by many other fish, including Manta Rays (Manta birostris; Hawaiian: Hāhālua).

Diving and observing everyday for a whole year is needed to view all the various fish and invertebrates living in this area, especially inside the coral structure.The path through the coral, heading towards the green buoy, ends when the coral ledge meets a large sand shelf at 20m. The coral ledge gives way to an all sand bottom that also hides a wealth of marine life. A large population of Hawaiian Garden Eels (Gorgasia hawaiiensis) populate the sandy bottom, They sway uniformly with the water flow to catch prey floating by. Various forms of crab and mantis shrimp hide in the sand. This is also a great place to view Flying Gurnards (Dacttylotena orientalis; Hn: Loloa’u) and be mesmerized by their colorful wings.
The bay also offers the most wonderful anomaly in my opinion: Spinner Dolphins (Stenella longirostris; Hn: Naia) that frequent the bay for resting and sleeping. Again, this is the busiest bay along 190 km of coastline, yet large pods of dolphins still elect to use this bay as a daytime resting site. It is a widely held belief that spinner dolphins need quiet and undisturbed rest to regain their energy for their nighttime open ocean fish hunts.Yet against this conventional wisdom, they still elect to use this busy harbor mouth as a place of rest and sleep. Even with the threats of numerous vessels racing above, tiger sharks congregating in the vicinity, and popularity of scuba divers swimming in the bay, the Spinner Dolphins are seen resting and sleeping frequently.

ULIULI KAI HOLO KA MANŌ: Where the sea is dark, sharks swim

For many decades, the fishing vessels, both commercial and recreational, have had a habit of throwing overboard their filleted fish carcasses and unused bait along this path. Inside the harbor, near the mouth, an official weigh station is overtly located and frequently used very near the alley.
Over the years, tiger sharks have been known to visit the weigh station for an easy meal. This is such a well-known occurrence that, as every vessel leaves or enters the harbor, there almost always will be a person on the bow scouting for tiger sharks.
Ancient Hawaiians, and still in today’s populace, have a cultural connection to the oceans. Their survival was dependent on sustainability of the reefs. They understood, and knew, that if there were no fish in the oceans, they would not survive. They also saw how individual fish roles for the betterment of the reefs were similar to individual human’s roles for the betterment of society. These assimilations were written down as olelo no’eau, proverbs, that were told through generations.

Hawaiians knew that as you dropped off the reef into the dark deeper waters, the big sharks roamed. But besides the danger that this posed, they also respected the sharks as aumakua, the spiritual embodiment of ancestors,. These sharks were revered and respected. When an aumakua was made present, it was the sign of forthcoming good or ill will, depending on how the aumakua was treated.

“He manō holo ‘āina ke ali’i.” The Chief is a shark that travels on land.”
The tiger shark was also known to be the top of the ocean animal chain. It ruled all the waters and all the fish. Much like the reverence of the tribal chief, who ruled over the land and people, he was assimilated to be a shark that walks on the land.

THE TIGER SHARK APPEARS

Wyland and I entered the water from our vessel that was moored to one of three subsurface mooring balls. Our short swim began along the lava ledge and right into the sandy path, passing over healthy corals and the many fish that inhabit the reef. vessels overhead skimmed across the surface at normal speed, leaving a wake that danced with the light rays penetrating the water surface. As we approached the path, I could see a fish carcass lying on the sand, an obvious throw-over from one of the passing vessels. Seeing this gave great hope that one of Honokohau’s resident tiger sharks would surely appear.

We positioned ourselves in the sand about 10 meters away from the carcass, hiding behind boulder sized coral heads. Within minutes, a small male tiger shark (~2.75m) came along to investigate. He made a couple of circles of the area (one pass was about 1m above my head), but the beautiful little animal showed little interest in the carcass, and quickly swam off. As I wondered why the shark didn’t eat the carcass, a large female tiger shark (~4.5m) appeared directly in front of me, obviously scaring off the smaller shark.

It is amazing how this large animal suddenly appeared. I liken its appearance to the Cheshire Cat of “Alice in Wonderland” fame. I was staring at a single small coral head when the shark just materialized in front of it. Imagine – A 4.5m shark was able to simply appear in front of me from just 3 meters away! This lends proof to the concept of the tiger shark being a professional hunter. The animal knows how to stay out of your visual range and only appears when it allows you to see it. I was looking directly in the direction if the shark before realizing that I was looking at it, and only then did I see it because it allowed me to. This happened about 3 times within 1-2m of me. The amazing ability of this large animal to just appear in such close proximity in just a sudden moment is chilling. It was like watching a magician on stage, except this wasn’t a trick. This wasn’t slight of hand or use of mirrors. This animal is a true hunter and a master of the sneak attack.

After the animal ate the carcass, it swam off hastily and left a sandy cloud in its wake. Seeing this wonderful display reminded me of how important a role these animals play in the environment. They are apex predators and are needed for the reef ecosystem because they clean dead and rotting animal flesh.

The naming of the shark as “tiger” goes beyond the stripes that define it. These animals move as stealthy as a feline, with just the same confidence and nonchalant attitude of being the owner of the area. Just as the Cheshire Cat moves invisibly through Alice’s world, appearing with a sneer of confidence and seen only when it wants others to see it, tiger sharks move through the water with the same confidence and grace of the clandestine feline, and then disappears behind its own sandy cloud screen.

The best seasons to scuba dive this wonderful anomaly is spring, summer, and autumn. Hawaii Diving Tours, a scuba diving tour company, dives this site almost everyday of the week, and at different times of the day. Their knowledge and experience in Honokohau are unprecedented. They offer personalized eco-tours and underwater imaging consulting. Also, other dives such as the Manta Ray night dive and BlackWater are also available. You may visit their website and book tours at: hawaiidivingtours.com

THE GLOBAL SHARK PROBLEM (by Wyland)

Sharks need protection. Unfortunately, the thing that can protect them is the same thing that’s killing them each year in massive numbers. In case you haven’t guessed, that “thing” is us.
People. We’re the biggest threat to the future of these apex predators.
Sharks, like terrestrial apex predators, maintain the environmental equilibrium. They keep our oceans and marine ecosystems healthy. It is shown that without healthy shark populations, many other species are affected. The end result, is an unhealthy planet.
It is estimated that we are killing over 100 million sharks a year, mostly for the demand of shark fin soup. Yet, we do this even as scientists have confirmed that sharks are critical to the health of the ocean, that without them, the entire balance of our ocean ecosystem could crash. Without healthy populations of sharks, the life in the sea will continue to decline and will collapse.

Shark populations can no longer take the extraction numbers that are seen today. Many species of shark populations have declined dramatically; some species are less than 80% of the original populations. Great white sharks, for example, have thrived for at least 16 million years. Today, they are listed as vulnerable by the IUCN.

Sharks can take years to reach maturity. The slow ability to regenerate combined with unsustainable fishing practices are a devastating combination and clearly show the remarkable ability of humans to change the world in a very short time. Sadly many of the sharks are killed only for their fins. They are inhumanely chopped off and thrown overboard to die slow death. The fins are then frozen or dried and most often shipped to Asia where they are used for soup.

Now, we humans have a choice. We can keep killing these animals until all the dire predictions come true. Or we can become the protectors of one of our most ancient and vital species.

This can only be done by using the old environmental motto of: Think globally, act locally.

Sharks recognize no political boundaries. They migrate where they need to, across the oceans, covering many territories and, therefore, are susceptible to being harvested in places that offer no protection. To ensure that shark populations recover, we need as many local bans on shark finning as possible, until one day we can banish this terrible practice from the earth once and for all.

The good news is many countries are creating laws today that protect sharks. Governments are starting to see the value of healthy shark populations in relation to the health of coral reefs, our ocean, and tourism.

A dead shark has very little value, while a living shark can provide thousands of dollars to a city or country for tourism, not to mention that healthy sharkpopulations provide more fish that provide sustainable tourism like diving and snorkeling, giving value to the region.

It’s time for all countries and all people to unite and be champions for conservation of sharks and healthy oceans. It is time to put transparency on shark finning and overfishing that threatens all of us today.

For a list of the 24 currently named Tiger Sharks ID’d in Honokohau Harbor, please visit Jeff Milisen’s tiger shark page at milisenphotography.yolasite.com

You’ll see a shark by the name of “Ralphy,” which is named after the author’s son.

AUTHORS

CHARLIE FASANO has a degree in Marine Biology from the University of North Carolina at Wilmington. He was previously employed by NOAA Southeast Fisheries Science Center and University of Miami Collaborative Institute of Marine and Atmospheric Science as a Reef Restoration Scientist. Since moving to Hawai’i, he started his own underwater production film company.

WYLAND is an internationally renowned marine artist and conservationist.
For the 3 decades, he has painted the large life sized ocean murals on the sides of buildings and other structures around the world. There are 100 “Whaling walls” found around the world.
Since Wyland had an event the evening that we filmed the tigers, he asked me to make a video of the day to show his audience.
So I made this rough cut of the dive that day.
You can watch it here, it’s only 2 min.

WORDS and PICTURES by Charlie Fasano & Wyland

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